The present invention relates to an inkjet printer, and more particularly, relates to an inkjet printer capable of adequately controlling operations of a printer depending on a defective nozzle occurrence situation in which ink droplets are not ejected from a nozzle of a recording head.
The inject printer carries out printing by ejecting fine ink droplets from many nozzles formed in a recording head towards a recording medium to land the ink droplets on the recording medium. In such an inkjet printer, when clogging occurs in a nozzle with dried ink, dust or other substances, the nozzle becomes a defective nozzle from which the ink droplets are not ejected, causing the generation of turbulence in the image.
Thus, proposed in Patent Document 1 is a technology that provides detection means for detecting an ejection state of ink droplets from each of the nozzles of a recording head and cleaning means for cleaning the recording head, detecting a defective nozzle from which the ink droplets are not ejected by the detection means, and when the defective nozzle is detected, cleaning the recording head by the cleaning means to recover the state of the recording head.
Further, proposed in Patent Document 2 is a technology that distributes image data so that a plurality of full-line type of recording heads complement each other to record the image data, and when a defective nozzle is present, overlapping the image data of the defective nozzle onto image data of a corresponding nozzle of another recording head to cause the other nozzle to substitute the defective nozzle.
[Patent Document 1] Japanese Patent Publication Laid-Open No. HEI 8-118679
[Patent Document 2] Japanese Patent Publication Laid-Open No. HEI 10-6488
In the case where an ink to be used is a light-colored yellow ink, defective nozzles which occur in several nozzles of many nozzles in the recording head are less visible, so that a user may continue printing without minding it. On the other hand, in the case of dark-colored black ink, magenta ink, and cyan ink, the presence of only one defective nozzle can be visible in the image and thereby the user may mind it.
Further, when a plurality of defective nozzles occur in the recording head(s), the case in which they are sporadically present in many nozzles of one recording head or sporadically present in a plurality of recording heads is less visually apparent as compared to the case in which the defective nozzles concentrate at adjacent nozzles of one recording head or concentrate at one recording head of the plurality of recording heads even if the number of defective nozzles is the same in both cases.
In addition, such a visual problem of defective nozzles differs depending on the type of recording medium. For example, when a defective nozzle occurs in an inkjet textile printing apparatus, the case of printing on a towel is less apparent as compared to the case of printing on a cloth having relatively smooth surface.
However, with the technology as described in Patent Document 1 that carries out the cleaning operation when a defective nozzle is detected, printing is interrupted every time when a defective nozzle is detected even if the occurrence of the defective nozzle is minor and less apparent in the image, so that there are problems of the time loss during the printing interruption, the consumption of ink associated with the cleaning operation and other disadvantages.
Further, a technology that when defective nozzles are detected, causes information such as the number of the defective nozzles to be displayed for every recording head and makes a user confirm the display to commit determination of whether to carry out the cleaning operation to the user is thought, however, the user always needs to stand by so as to confirm the display, and in this case also, printing is interrupted every time when a defective nozzle is detected, so that the problem of occurring the time loss is not solved at all.
Meanwhile, in the case of the technology described in Patent Document 2, printing is not immediately interrupted when a defective nozzle occurs, but the presence of other nozzle capable of complementing the defective nozzle when occurring is indispensable, so that the technology cannot be applied to all of the recording heads or all of the inkjet printers.